Deep sleep mode for WLAN communication systems

ABSTRACT

A WLAN (Wireless Local Area Network) communication device for performing communication in a WLAN network is provided that comprises a physical connection unit, a physical connection oscillator, and a control unit. The physical connection unit is for providing a physical connection of the WLAN communication device to a wireless communication medium. The physical connection oscillator is for providing a physical connection clock signal to the physical connection unit. The control unit is for controlling operation of the physical connection oscillator. The WLAN communication device is operable in a communication mode and in a deep sleep mode. The control unit is adapted to deactivate the physical connection oscillator when the deep sleep mode is entered. Embodiments may provide an extended reduction of the power consumption of the WLAN communication device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present application relates to WLAN (Wireless Local Area Network)communication devices for performing communication in a WLAN network andcorresponding integrated circuit chips, computer systems and methods,and in particular to standby modes thereof.

2. Description of the Related Art

A wireless local area network is a flexible data communication systemimplemented as an extension to or as an alternative for a wired LAN.Using radio frequency or infrared technology, WLAN systems transmit andreceive data over the air, minimizing the need for wired connections.Thus, WLAN systems combine data connectivity with user mobility.

Today, most WLAN systems use spread spectrum technology, a widebandradio frequency technique developed for use in reliable and securecommunication systems. The spread spectrum technology is designed totrade off bandwidth efficiency for reliability, integrity and security.Two types of spread spectrum radio systems are frequently used:frequency hopping and direct sequence systems.

The standard defining and governing wireless local area networks thatoperate in the 2.4 GHz spectrum is the IEEE 802.11 standard. To allowhigher data rate transmissions, the standard was extended to 802.11 bwhich allows data rates of 5.5 and 11 Mbps in the 2.4 GHz spectrum.Further extensions exist.

Generally, WLAN systems comprise one or more access points that connectto a wired network and remote client devices that connect to the accesspoints through wireless links. In a peer-to-peer WLAN system, the clientdevices may also communicate directly with each other. The remote clientdevices are usually portable computer systems with WLAN communicationdevices, often referred to as WLAN cards or modules, installed. Sinceremote devices are usually mobile and often use battery power, the powerconsumption of the system required for WLAN-related activities is animportant feature affecting the battery lifetime and therefore the userfriendliness of the system.

In order to reduce the WLAN-related power consumption, many conventionalWLAN cards can be operated in a standby mode when no exchange of datapackets between the host computer system and an access point isrequired. Two types of standby modes are usually applied: in a listeningmode, the WLAN card listens periodically for traffic from the accesspoint including beacon signals announcing the presence and readiness ofthe access point. However, no data packets are exchanged with the hostcomputer system. In a sleep mode the link to the access point isdisabled. A majority of the WLAN card circuitry is turned off except forcertain critical parts.

According to prior art techniques, the parts of the WLAN card circuitrythat are kept active during the sleep mode include the very stablereference oscillator that governs the operation of the WLAN cardcircuitry by providing a base clock signal and stabilizes the operationof the radio circuitry. This usually leads to a still considerable powerconsumption in the sleep mode: conventional WLAN cards often consume15-20 mA of current while in the sleep mode, whereof 8-9 mA are consumedsolely by the reference oscillator.

In order to extend the battery lifetime of the host computer system,known WLAN cards often extend the time of remaining in the sleep mode.While the WLAN card is in the sleep mode, incoming data packets arebuffered at the access point. They may only be retrieved when the WLANcard enters the listening mode in order to find out whether there aredata packets queued at the access point and transitions from the standbymode to a communication mode if this is the case. In consequence,conventional WLAN systems often defer the data exchange between theaccess point and the client device. This may lead to further problems inachieving efficient data rates.

Further, the access points buffering the data packets while the clientdevice is in the sleep mode are generally permitted to dump unread datapackets after a specified time and these data packets go unretrieved.Therefore, conventional WLAN systems also have the disadvantage ofusually suffering from considerable data loss.

SUMMARY OF THE INVENTION

An improved WLAN communication device for performing communication in aWLAN network and corresponding integrated circuit chips, computersystems and methods are provided that may overcome the disadvantages ofthe conventional approaches. Embodiments may provide a deep sleep modefor operating a WLAN communication device that may have the advantage ofconsuming significantly less power in the deep sleep mode than in aconventional sleep mode. In other embodiments, the tradeoff betweenextending battery lifetime of the host computer system and achievingefficient data rates may be enhanced. In further embodiments, increasedbattery lifetime may be achieved while not deferring the exchange ofdata packets between the access point and the client device. In stillfurther embodiments, battery lifetime may be increased while data lossdue to deferred reception may be prevented.

In one embodiment, a WLAN communication device for performingcommunication in a WLAN network is provided comprising a physicalconnection unit, a physical connection oscillator, and a control unit.The physical connection unit is for providing a physical connection ofthe WLAN communication device to a wireless communication medium. Thephysical connection oscillator is connected to the physical connectionunit for providing a physical connection clock signal to the physicalconnection unit. The control unit is connected to the physicalconnection oscillator for controlling operation of the physicalconnection oscillator. The WLAN communication device is operable in acommunication mode for transmitting and/or receiving data packets and ina first standby mode. The control unit is adapted to deactivate thephysical connection oscillator when the WLAN communication device entersthe first standby mode.

In another embodiment, an integrated circuit chip for performingcommunication in a WLAN network is provided comprising a physicalconnection circuit, a physical connection oscillator circuit, and acontrol circuit. The physical connection circuit is for providing aphysical connection of the integrated circuit chip to a wirelesscommunication medium. The physical connection oscillator circuit isconnected to the physical connection circuit for providing a physicalconnection clock signal to the physical connection circuit. The controlcircuit is connected to the physical connection oscillator circuit forcontrolling operation of the physical connection oscillator circuit. Theintegrated circuit chip is operable in a communication mode fortransmitting and/or receiving data packets and in a first standby mode.The control circuit is adapted to deactivate the physical connectionoscillator circuit when the integrated circuit chip enters the firststandby mode.

In a further embodiment, a computer system for performing communicationin a WLAN network is provided comprising a physical connection device, aphysical connection oscillator, and a control device. The physicalconnection device is for providing a physical connection of the computersystem to a wireless communication medium. The physical connectionoscillator is connected to the physical connection device for providinga physical connection clock signal to the physical connection device.The control device is connected to the physical connection oscillatorfor controlling operation of the physical connection oscillator. Thecomputer system is operable in a communication mode for transmittingand/or receiving data packets and in a first standby mode. The controldevice is adapted to deactivate the physical connection oscillator whenthe computer system enters the first standby mode.

In yet another embodiment, a method of operating a WLAN communicationdevice for performing communication in a WLAN network is provided. Aphysical connection unit is operated for providing a physical connectionof the WLAN communication device to a wireless communication medium. Aphysical connection oscillator is operated for providing a physicalconnection clock signal to the physical connection unit. A control unitis operated for controlling operation of the physical connectionoscillator. The WLAN communication device is operated in a communicationmode for transmitting and/or receiving data packets and in a firststandby mode. The physical connection oscillator is deactivated when theoperation of the WLAN communication device enters the first standbymode.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated into and form a part of thespecification for the purpose of explaining the principles of theinvention. The drawings are not to be construed as limiting theinvention to only the illustrated and described examples of how theinvention can be made and used. Further features and advantages willbecome apparent from the following and more particular description ofthe invention, as illustrated in the accompanying drawings, wherein:

FIG. 1 is a block diagram illustrating the components of aWLAN-compatible computer system according to an embodiment;

FIG. 2 is a block diagram illustrating the components of the deep sleepcontrol circuit comprised within the WLAN-compatible computer system ofFIG. 1 according to an embodiment;

FIG. 3 is a flow diagram illustrating a clock ramp-up process accordingto an embodiment;

FIG. 4 is a flow diagram illustrating a deep sleep clock determinationprocess according to an embodiment;

FIG. 5 is a flow diagram illustrating a deep sleep entering processaccording to an embodiment; and

FIG. 6 is a flow diagram illustrating a deep sleep abandoning processaccording to an embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The illustrative embodiments of the present invention will be describedwith reference to the figure drawings, wherein like elements andstructures are indicated by like reference numbers.

Referring now to FIG. 1, a WLAN-compatible computer system according toan embodiment is shown. The computer system may comprise a WLANcommunication device 120.

According to the embodiment, the WLAN communication device 120 maycomprise a physical connection circuit 145 for providing a physicalconnection of the WLAN communication device 120 to a wirelesscommunication medium over which communication signals can be exchangedwith a WLAN communication counterpart. For instance, the physicalconnection circuit 145 may comprise a radio circuit or infrared circuitfor sending and/or receiving radio or infrared signals respectively overthe wireless communication medium. Other transmission/receptiontechniques may be applied. The physical connection circuit 145 maycomprise an internal oscillator for generating the communicationsignals.

The WLAN communication device 120 may comprise a physical connectionoscillator 150 that is connected to the physical connection circuit 145for providing a physical connection clock signal to the physicalconnection circuit 145. The physical connection clock signal may be usedfor stabilizing the frequency generated by the internal oscillatorwithin the physical connection circuit 145. In an embodiment, thephysical connection oscillator 150 may be a quartz oscillator generatingthe physical connection clock signal at a frequency of 44 MHz. Othertypes of oscillators operating at other frequencies may be applied.

According to an embodiment, the WLAN communication device 120 maycomprise a MAC (Medium Access Control) circuit 130 for managingcommunication in the WLAN network by coordinating access to the wirelesscommunication medium. The WLAN communication device 120 may furthercomprise a BBP (Base Band Processor) circuit 135 for converting thecommunication signals interchangeable over the wireless communicationmedium into digital data packets processable by the MAC circuit 130and/or vice versa. The BBP circuit 135 may be connected to the physicalconnection circuit 145 for exchanging the communication signals and tothe MAC circuit 130 for exchanging the digital data packets.

Further, the WLAN communication device 120 may comprise a deep sleepcontrol circuit 140 connected to the physical connection oscillator 150for controlling operation of the physical connection oscillator 150.According to the embodiment, the deep sleep control circuit 140 mayfurther be connected to the MAC circuit 130 for exchanging controlsignals during the processes of entering and/or abandoning a deep sleepmode of the WLAN communication device 120 which will be described below.

In an embodiment, the physical connection circuit 145 may comprise afrequency divider for generating a main clock signal by dividing thefrequency of the physical connection clock signal received from thephysical connection oscillator 150. For example, the frequency dividerof the physical connection circuit 145 may convert a 44 MHz physicalconnection clock signal into a 22 MHz main clock signal. In anembodiment, the physical connection circuit 145 may be connected to theMAC circuit 130 and/or the BBP circuit 135 and/or the deep sleep controlcircuit 140 for providing the main clock signal to the MAC circuit 130and/or the BBP circuit 135 and/or the deep sleep control circuit 140,respectively.

Further, the MAC circuit 130 and the BBP circuit 135 may be comprisedwithin an integrated baseband medium access circuit 125. In anotherembodiment, the deep sleep control circuit 140 may also be comprisedwithin the integrated baseband medium access circuit 125. In yet anotherembodiment, the WLAN communication device 120 may not comprise anintegrated baseband medium access circuit 125, but the MAC circuit 130,the BBP circuit 135, and the deep sleep control circuit 140 as separateindividual circuits.

In another embodiment, the WLAN communication device 120 may compriseadditional internal oscillators besides the physical connectionoscillator 150 for providing clock signals to certain components of theWLAN communication device 120.

The WLAN device 120 may be installed on a host computer systemcomprising a CPU (Central Processing Unit) 105 for providing WLANcompatibility to the computer system. The MAC circuit 130 of the presentembodiment may be connected to the CPU 105 for exchanging digital datapackets and/or control signals for entering and/or abandoning thebelow-described deep sleep mode of the WLAN communication device 120.According to the embodiment, the CPU 105 may further be connected to thedeep sleep control circuit 140 for sending control signals for enteringand/or abandoning the below-discussed deep sleep mode to the deep sleepcontrol circuit 140.

As illustrated, the deep sleep control circuit 140 may be connected toan analog clock oscillator 110 and a digital clock oscillator 115 withinthe host computer system for receiving a clock signal from the analogclock oscillator 110 and/or the digital clock oscillator 115 while theWLAN communication device 120 is in the below-described deep sleep mode.In other embodiments, the deep sleep control circuit 140 may beconnected to either an analog clock oscillator 110 or a digital clockoscillator 115 only. In further embodiments, the deep sleep controlcircuit 140 may be connected to a plurality of analog and/or digitalclock oscillators. In still a further embodiment, the analog clockoscillator 110 and/or the digital clock oscillator 115 may be comprisedwithin the WLAN communication device 120 or within the integratedbaseband medium access circuit 125.

Different types of oscillators may serve as the analog clock oscillator110. For instance, the analog clock oscillator 110 may be a XO (crystaloscillator) oscillator. In one embodiment, the XO oscillator may be anuncompensated XO oscillator. In other embodiments, the XO oscillator maybe a compensated XO oscillator, e.g., a voltage-controlled crystaloscillator, a temperature compensated crystal oscillator, or anoven-controlled crystal oscillator.

According to the embodiment, the analog clock oscillator 110 may emit aclock signal at a frequency of 32.768 kHz. In other embodiments, theclock signal generated by the analog clock oscillator 110 may have otherfrequencies. Combinations of the embodiments may be implemented.

In an embodiment, the digital clock oscillator 115 may be a programmabledigital clock oscillator emitting a clock signal at a frequency that canbe selected from a certain frequency range. For instance, a clock signalfrequency may be selected from a frequency range extending from 32 kHzto 22 MHz. In other embodiments, the clock signal frequency may beselected from a frequency range extending from 16 kHz to 1 MHz or fromany other frequency range. In a further embodiment, the digital clockoscillator 115 may be a watchdog oscillator for ensuring robust behaviorof components of the host computer system in noisy environments withpoor or unreliable power supplies. Combinations of the embodiments maybe realized.

Turning now to FIG. 2, the components of the deep sleep control circuit140 according to an embodiment are shown. The deep sleep control circuit140 may comprise a timing counter 230 for counting the number of timeintervals of a predetermined length that have elapsed since the WLANcommunication device 120 has entered the below-discussed deep sleepmode.

Accordingly, the deep sleep control circuit 140 may further comprise atiming control circuit 220 connected to the timing counter 230 formaking the timing counter 230 start and/or stop counting by sending astart counting signal or a stop counting signal, respectively, to thetiming counter 230. Further, the timing control circuit 220 may beconnected to the CPU 105 and the MAC circuit 130 for receiving orexchanging, respectively, control signals for entering and/or abandoningthe below-described deep sleep mode. According to the embodiment, thetiming control circuit 220 may also be connected to the physicalconnection oscillator 150 for controlling operation of the physicalconnection oscillator 150.

In other embodiments, the timing control circuit 220 and the timingcounter 230 may be combined in one single circuit.

The deep sleep control circuit 140 further comprises a multiplexer 210for forwarding the clock signals received from the physical connectioncircuit 145 and the analog clock oscillator 110 and/or the digital clockoscillator 115 to the timing control circuit 220 and the timing counter230. In other embodiments, the multiplexer 210 may be located on theWLAN communication device 120 outside the deep sleep control circuit 140or outside the integrated baseband medium access circuit 125.

In an embodiment, frequency dividers may be installed between themultiplexer and the physical connection circuit 145 and/or between themultiplexer 210 and the analog clock oscillator 110 and/or between themultiplexer 210 and the digital clock oscillator 115. In one embodiment,a frequency divider may divide the 22 MHz main clock signal from thephysical connection circuit 145 by 2,750 in order to generate an 8 kHzclock signal provided to the multiplexer 210. In another embodiment, afrequency divider may divide the 32.768 kHz clock signal from the analogclock oscillator 110 by 4 in order to generate a clock signal of about 8kHz provided to the multiplexer 210. In yet another embodiment, afrequency divider may generate a clock signal of about 8 kHz by dividingthe clock signal of a programmable frequency from the digital clockoscillator 115 accordingly. Clock signals of other frequencies may beprovided to and/or generated by the frequency dividers.

Further, the deep sleep control circuit 145 may comprise a frequencydivider acting on the frequency of the clock signal provided from themultiplexer 210 to the timing control circuit 220 and the timing counter230. In one embodiment, this frequency divider may convert a clocksignal of (about) 8 kHz into a clock signal of (about) 4 kHz. In otherembodiments, this frequency divider may convert a clock signal of afrequency other than 8 kHz into a clock signal of a frequency other than4 kHz.

In other embodiments, the described frequency dividers connected to themultiplexer 210 may be located outside the deep sleep control circuit140 or outside the integrated baseband medium access circuit 125.

The timing controller 230 may count the number of time intervals elapsedsince the WLAN communication device 120 has entered the below-describeddeep sleep mode based on the clock signal received over the multiplexer210. In one embodiment, time intervals of 1/1024 s may be counted. Inother embodiments, the counted time intervals may have other lengths.The timing counter 230 may be programmable in order to select the lengthof the time intervals to be counted.

The deep sleep control circuit 140 of the present embodiment may beadapted to determine whether a clock signal from the analog clockoscillator 110 and/or the digital clock oscillator 115 is available tothe multiplexer 210. The deep sleep control circuit 140 may further beadapted to determine how many clock signals are available to themultiplexer 210 and/or whether the available clock signals are receivedfrom analog or digital clock oscillators. Further, the deep sleepcontrol circuit 140 may be adapted to determine the frequency of theavailable clock signals. Moreover, the deep sleep control circuit 140may be capable of determining a preferred clock signal if more than oneclock signal is available to the multiplexer 210. For instance, thepreferred clock signal may be determined by reading preference valuesfor the individual available clock signals from a preference table.Furthermore, the deep sleep control circuit 140 may be arranged forcontrolling the setting of the multiplexer 210 so that only thepreferred clock signal may be passed through the multiplexer 210. Inother embodiments, the above-described determination and control stepsmay be accomplished by individual or combined dedicated circuits withinthe deep sleep control circuit 140 and/or the integrated baseband mediumaccess circuit 125 and/or the WLAN communication device 120. In furtherembodiments, at least part of the above-described determination andcontrol steps may be accomplished by the timing control circuit 220and/or the MAC circuit 130. Combinations of the embodiments may berealized.

According to an embodiment, the WLAN communication device 120 may beoperable in a communication mode for exchanging digital data packetswith a host computer system and exchanging corresponding communicationsignals with a WLAN communication counterpart, e.g., an access point oranother WLAN communication device, over the wireless communicationmedium. The communication mode may comprise a reception mode duringwhich the WLAN communication device 120 is detecting the communicationsignals, demodulating and converting the communication signals intodigital data packets and passing the digital data packets to the hostcomputer system. Further, the communication mode may comprise atransmission mode during which the WLAN communication device ismodulating and converting the digital data packets into communicationsignals and sending the communication signals over the wirelesscommunication medium. According to the embodiment, all the components ofthe WLAN communication device 120 may be active during the communicationmode.

The WLAN communication device 120 may further be operable in at leastone standby mode. The standby mode may comprise a listening mode duringwhich the WLAN communication device 120 is listening for traffic from aWLAN communication counterpart, but is not passing any data to the hostcomputer system. While the WLAN communication device 120 is in thelistening mode, part of its components, e.g., the components only neededfor communicating with the host computer system, may be inactive whileother components including the physical connection circuit 145 and thephysical connection oscillator 150 may be active. The WLAN communicationdevice 120 may consume less power in the listening mode than in thecommunication mode.

In another embodiment, the standby mode may comprise a sleep mode. Whilethe WLAN communication device 120 is in the sleep mode, no digital datapackets may be exchanged with a host computer system. Also, no link to aWLAN communication counterpart may be established during the sleep mode.A majority of the circuitry of the WLAN communication device 120 may beturned off during the sleep mode except for certain critical partsincluding the physical connection oscillator 150. According to theembodiment, the WLAN communication device 120 may consume less power inthe sleep mode than in the listening mode and/or the communication mode.In one embodiment, the WLAN communication device 120 may consume 15-20mA of current while in the sleep mode, whereof 8-9 mA may be consumed bythe physical connection oscillator 150.

In a further embodiment, the standby mode may comprise a deep sleepmode. While in the deep sleep mode, the WLAN communication device 120may not exchange any digital data packets with the host computer system.No link to WLAN communication counterparts may be established during thedeep sleep mode. All the components of WLAN communication device 120that are inactive during an above-described sleep mode may also beinactive during the deep sleep mode. Additionally, the physicalconnection oscillator 150 may be inactive during the deep sleep mode. Inanother embodiment, the MAC circuit 130 and/or the physical connectioncircuit 145 may also be inactive during the deep sleep mode. The WLANcommunication device 120 may consume less power in the deep sleep modethan in the sleep mode and/or the listening mode and/or thecommunication mode. According to an embodiment, the WLAN communicationdevice 120 may consume 1-2 mA of current during the deep sleep mode.

Embodiments combining the described communication and standby modes mayalso be implemented.

FIG. 3 illustrates a clock ramp-up process that may be performed by theWLAN communication device 120 upon being activated, e.g., after a reset.The clock ramp-up process may also be performed when the WLANcommunication device 120 abandons the deep sleep mode. In step 310, anactivate signal may be sent from the timing control circuit 220 to thephysical connection oscillator 150. Upon reception of the activatesignal, the physical connection oscillator 150 may be activated, i.e.the physical connection oscillator 150 may generate the physicalconnection clock signal. In another embodiment, also the physicalconnection circuit 145 may be activated once the physical connectionoscillator 150 has started to generate the physical connection clocksignal. In a further embodiment, additional internal clock oscillatorsbesides the physical connection oscillator 150 (and besides the analogclock oscillator 110 and the digital clock oscillator 115, in case theyare comprised within the WLAN communication device 120) may also beactivated.

In step 320, an activate signal may be sent from the timing controlcircuit 220 to the MAC circuit 130 for activating the MAC circuit 130.Once the MAC circuit 130 is active, the MAC circuit 130 may return anactivate confirmation signal to the timing control circuit 220 in step330 for acknowledging the activation.

In an embodiment, the clock ramp-up process may last 1-4 ms.

Referring now to FIG. 4, a flow diagram illustrating a deep sleep clockdetermination process according to an embodiment is shown. The deepsleep clock determination process may be performed subsequently to theclock ramp-up process or at any later time prior to entering the deepsleep mode.

In step 410, the system may determine whether a clock signal from theanalog clock oscillator 110 and/or the digital clock oscillator 115 isavailable to the multiplexer 210. This may comprise determining how manyclock signals are available and whether the available clock signals arereceived from the analog clock oscillator 110 and/or the digital clockoscillator 115.

In step 420 it may be queried whether clock signals from both the analogclock oscillator 110 and the digital clock oscillator 115 are available.If this is the case, the system may determine in step 440 which of theavailable clock signals is preferred and proceed to step 450. Otherwise,it may be queried in step 430 if a clock signal from either the analogclock oscillator 110 or the digital clock oscillator 115 is available.If so, the multiplexer may be set in step 450 to the input from theavailable or preferred clock oscillator, respectively. Otherwise, themultiplexer may be set in step 460 to the input from the physicalconnection circuit 145.

FIG. 5 is a flow diagram illustrating a deep sleep entering processaccording to an embodiment. In step 510, a deep sleep request signal maybe sent from the MAC circuit 130 to the timing control circuit 220. Inother embodiments, the deep sleep request signal may be sent to thetiming control circuit from the CPU 105 and/or a communicationcounterpart, e.g., an access point, within the WLAN network. In suchembodiments, the deep sleep request signal may be sent to the timingcontrol circuit 220 directly and/or over the MAC circuit 130. In step520, a request confirmation signal may be sent from the timing controlcircuit 220 to the MAC circuit 130 if the deep sleep request signal hasbeen received. In other embodiments, the request confirmation signal maybe returned to the sender of the deep sleep request signal which may bedifferent from the MAC circuit 130, as indicated above.

According to the illustrated embodiment, the MAC circuit 130 may send adeep sleep duration signal to the timing control circuit 220 in step530. The deep sleep duration signal may indicate a number of timeintervals of a predetermined length corresponding to the intendedduration of the deep sleep mode, after which the deep sleep mode may beabandoned automatically. In an embodiment, the deep sleep durationsignal may indicate an indeterminate duration of the deep sleep mode. Inthis embodiment, the deep sleep mode may not be abandoned automaticallybut, e.g., upon reception of a deep sleep abandon signal from the CPU105 or upon a reset of the WLAN communication device 120.

According to further embodiments, the deep sleep duration signal may besent from the CPU 105 and/or an access point within the WLAN network tothe timing control circuit 220. In such embodiments, the deep sleepduration signal may be sent to the timing control circuit 220 directlyor over the MAC circuit 130. In still a further embodiment, the WLANcommunication device 120 may be capable of negotiating a duration of thedeep sleep mode with the CPU 105 and/or a communication counterpart,e.g., an access point, within the WLAN network. The order of magnitudeof the deep sleep duration may extend from milliseconds to seconds.

In step 540, a counting start signal may be sent from the timing controlcircuit 220 to the timing counter 230 for making the timing counter 230start counting the number of time intervals that elapse. Upon receptionof the counting signal, the timing counter 230 may continuously countthe elapsed time intervals.

According to an embodiment, the WLAN communication device 120 maycomprise additional internal oscillators besides the physical connectionoscillator 150 (and besides the analog clock oscillator 110 and thedigital clock oscillator 115 in case they are comprised within the WLANcommunication device 120) for providing clock signals to certaincomponents of the WLAN communication device 120. These additionalinternal oscillators may be deactivated once the timing counter 230 hasstarted counting.

In step 550, a deactivate signal may be sent from the timing controlcircuit 220 to the MAC circuit 130. The MAC circuit 130 may bedeactivated upon reception of the deactivate signal.

In step 560, it may be queried whether at least one clock signal fromthe analog clock oscillator 110 and/or the digital clock oscillator 115is available to the multiplexer 210. If this is the case, a deactivatesignal may be sent from the timing control circuit 220 to the physicalconnection oscillator 150 in step 570. Upon reception of the deactivatesignal, the physical connection oscillator 150 may be deactivated.Subsequently, the physical connection circuit 145 may also bedeactivated according to an embodiment. If no clock signal is available,neither from the analog clock oscillator 110 nor from the digital clockoscillator 115, the deactivate signal may not be sent to the physicalconnection oscillator 150 and the deep sleep entering process may becomplete at this point.

Referring now to FIG. 6, a flow diagram illustrating a deep sleepabandoning process according to an embodiment is shown. The deep sleepabandoning process may lead to a transition of the WLAN communicationdevice 120 from the deep sleep mode to the sleep mode, the listeningmode or the communication mode.

In step 610, the timing control circuit 220 may determine whether thevalue of the timing counter 230 indicating the number of time intervalsthat have elapsed corresponds to the intended duration of the deep sleepmode. If this is the case, the system may proceed to step 630. If thisis not the case, it may be determined in step 620 whether a deep sleepabandon signal is received from the CPU 105. In one embodiment, the deepsleep abandon signal may be sent from the CPU 105 to the timing controlcircuit 220. In another embodiment, the deep sleep abandon signal may besent from the CPU 105 to the MAC circuit 130 which may forward the deepsleep abandon signal to the timing control circuit 220. If no deep sleepabandon signal is received, the deep sleep mode may not be abandoned. Ifa deep sleep abandon signal is received, the system may proceed to step630.

In step 630, a stop signal may be sent from the timing control circuit220 to the timing counter 230 for making the timing counter stopcounting the number of elapsed time intervals. In other embodiments, thetiming control circuit 220 may set the counter value to the number oftime intervals corresponding to the intended deep sleep duration duringthe deep sleep entering process. In such embodiments, the timing counter230 may count backwards and automatically stop counting when the countervalue reaches zero.

According to the embodiment, the WLAN communication device 120 mayperform the clock ramp-up process in step 640 once the timing counter230 has stopped counting. Subsequently, or at any later time prior toreentering the deep sleep mode, the deep sleep clock determination maybe performed in step 650.

In one embodiment, data packet strings containing a plurality of datapackets may be sent to and/or received from a communication counterpart,e.g., an access point or another WLAN communication device, within theWLAN network. Within a data packet string, the individual data packetsmay be separated by time intervals of a certain length, e.g., 100 ms.According to the embodiment, the WLAN communication device 120 mayperiodically switch between the communication mode and the deep sleepmode so that it may be in the deep sleep mode during the time intervalsseparating the data packets.

In other embodiments, the WLAN communication device 120 may be in thedeep sleep mode and periodically interrupt the deep sleep mode fortransitioning to the listening mode or any other mode for maintainingWLAN network connectivity. For instance, the WLAN communication device120 may abandon the deep sleep mode for entering the listening mode orthe communication mode each time a beacon signal indicating the presenceand readiness of a WLAN communication counterpart is sent to the WLANcommunication device 120. The beacon signal may include a DTIM (DeliveryTraffic Indication Message) message informing the WLAN communicationdevice 120 whether a data packet is awaiting delivery. In case a datapacket is queued at the WLAN communication counterpart, the WLANcommunication device 120 may enter or remain in the communication mode,respectively, for receiving the waiting data packet. Otherwise, the WLANcommunication device 120 may reenter the deep sleep mode upon receptionof the beacon signal. In further embodiments, not every beacon signalmay include a DTIM message and the WLAN communication device 120 mayabandon the deep sleep mode for receiving only those beacon signals thatcontain a DTIM message. In still other embodiments, the WLANcommunication device 120 may negotiate the duration of the deep sleepmode with the WLAN communication counterpart before entering the deepsleep mode.

According to an embodiment, the WLAN communication device 120 mayautomatically enter the sleep mode upon being activated, e.g., after areset of the WLAN communication device 120.

As apparent from the above description, embodiments may improve theefficiency of a WLAN-compatible computer system by reducing the systempower consumption. System efficiency may be measured, e.g., in terms ofthe amount of data transmitted/received in proportion to the powerconsumed. The described embodiments may provide an extended powerreduction for a WLAN system with main crystal oscillator switch-off.

As discussed above, the WLAN system may be switched off between tworeceive data frames. This may contain a switch-off of the chips and themain crystal oscillator. A separate clock source may be used for thewakeup timer and the system may have a controller which computes thenext wakeup event.

The presented deep sleep mode for a WLAN system may be applied incombination with AMD's Am1770 and/or Am1773 WLAN products.

While the invention has been described with respect to the physicalembodiments constructed in accordance therewith, it will be apparent tothose skilled in the art that various modifications, variations andimprovements of the present invention may be made in light of the aboveteachings and within the purview of the appended claims withoutdeparting from the spirit and intended scope of the invention. Inaddition, those areas in which it is believed that those of ordinaryskill in the art are familiar have not been described herein in order tonot unnecessarily obscure the invention described herein. Accordingly,it is to be understood that the invention is not to be limited by thespecific illustrative embodiments, but only by the scope of the appendedclaims.

1. A WLAN (Wireless Local Area Network) communication device forperforming communication in a WLAN network, the WLAN communicationdevice comprising: a physical connection unit for providing a physicalconnection of the WLAN communication device to a wireless communicationmedium; a physical connection oscillator connected to the physicalconnection unit for providing a physical connection clock signal to thephysical connection unit; and a control unit connected to the physicalconnection oscillator for controlling operation of the physicalconnection oscillator; wherein the WLAN communication device is operablein a communication mode for transmitting and/or receiving data packetsand in a first standby mode; and wherein the control unit is adapted todeactivate the physical connection oscillator when the WLANcommunication device enters the first standby mode.
 2. The WLANcommunication device of claim 1, further comprising a MAC (Medium AccessControl) unit for managing communication in the WLAN network bycoordinating access to the wireless communication medium.
 3. The WLANcommunication device of claim 2, wherein the MAC unit is connected tothe control unit for requesting a transition of the WLAN communicationdevice into the first standby mode by sending a first standby requestsignal to the control unit.
 4. The WLAN communication device of claim 3,wherein the control unit is adapted to receive the first standby requestsignal from the MAC unit and send a request confirmation signal to theMAC unit if the first standby request signal has been received.
 5. TheWLAN communication device of claim 2, wherein the control unit isconnected to the MAC unit for activating and/or deactivating the MACunit by sending to the MAC unit an activate signal or deactivate signal,respectively.
 6. The WLAN communication device of claim 5, wherein thecontrol unit is adapted to deactivate and/or activate the MAC unit whenthe WLAN communication device enters or abandons the first standby mode,respectively.
 7. The WLAN communication device of claim 6, wherein theMAC unit is adapted to be activated upon receiving the activate signalfrom the control unit and to send an activation confirmation signal tothe control unit if the MAC unit has been successfully activated.
 8. TheWLAN communication device of claim 2, wherein the MAC unit is connectedto the control unit for scheduling a duration of the first standby modeby sending a first standby duration signal to the control unit.
 9. TheWLAN communication device of claim 2, further comprising a BBP (BaseBand Processor) unit for converting communication signalsinterchangeable over the wireless communication medium into digital datapackets processable by the MAC unit and/or vice versa.
 10. The WLANcommunication device of claim 9, wherein the physical connection unitand the BBP unit are connected for exchanging the communication signals.11. The WLAN communication device of claim 9, wherein the BBP unit isconnected to the MAC unit for exchanging the digital data packets. 12.The WLAN communication device of claim 9, further comprising anintegrated baseband medium access unit and wherein the MAC unit and theBBP unit are comprised within the integrated baseband medium accessunit.
 13. The WLAN communication device of claim 12, wherein the controlunit is comprised within the integrated baseband medium access unit. 14.The WLAN communication device of claim 1, wherein the physicalconnection unit comprises a frequency divider for generating a mainclock signal by dividing the frequency of the physical connection clocksignal.
 15. The WLAN communication device of claim 14, wherein thephysical connection unit is connected to the control unit for providingthe main clock signal to the control unit.
 16. The WLAN communicationdevice of claim 14, further comprising a MAC (Medium Access Control)unit for managing communication in the WLAN network by coordinatingaccess to the wireless communication medium, and wherein the physicalconnection unit is connected to the MAC unit for providing the mainclock signal to the MAC unit.
 17. The WLAN communication device of claim14, further comprising: a MAC (Medium Access Control) unit for managingcommunication in the WLAN network by coordinating access to the wirelesscommunication medium; and a BBP (Base Band Processor) unit forconverting communication signals interchangeable over the wirelesscommunication medium into digital data packets processable by the MACunit and/or vice versa; wherein the physical connection unit isconnected to the BBP unit for providing the main clock signal to the BBPunit.
 18. The WLAN communication device of claim 1, wherein the controlunit is adapted to deactivate and/or activate the physical connectionoscillator by sending to the physical connection oscillator a deactivatesignal or activate signal when the WLAN communication device enters orabandons the first standby mode, respectively.
 19. The WLANcommunication device of claim 1, further comprising at least oneinternal oscillator in addition to the physical connection oscillatorfor providing a clock signal to at least one component of the WLANcommunication device.
 20. The WLAN communication device of claim 19,wherein the control unit is connected to the at least one internaloscillator for deactivating and/or activating the at least one internaloscillator by sending a deactivate signal or activate signal to the atleast one internal oscillator when the WLAN communication device entersor abandons the first standby mode, respectively.
 21. The WLANcommunication device of claim 1, adapted to be installed on a hostcomputer system comprising a CPU (Central Processing Unit) for providingWLAN communication functionality to the host computer system.
 22. TheWLAN communication device of claim 21, wherein the CPU is connected tothe control unit for making the WLAN communication device abandon thefirst standby mode by sending a first standby abandon signal to thecontrol unit.
 23. The WLAN communication device of claim 21, furthercomprising a MAC (Medium Access Control) unit for managing communicationin the WLAN network by coordinating access to the wireless communicationmedium and wherein the MAC unit is connected to the CPU for exchangingdigital data packets.
 24. The WLAN communication device of claim 1,adapted to receive at least one first standby clock signal from at leastone first standby clock oscillator while the WLAN communication deviceis in the first standby mode.
 25. The WLAN communication device of claim24, wherein the control unit is connected to the at least one firststandby clock oscillator for receiving the at least one first standbyclock signal.
 26. The WLAN communication device of claim 24, furtheradapted to determine before entering the first standby mode whether theat least one first standby clock signal is available to the WLANcommunication device.
 27. The WLAN communication device of claim 24,further adapted to determine before entering the first standby modewhether more than one first standby clock signal is available to theWLAN communication device.
 28. The WLAN communication device of claim27, further adapted to determine before entering the first standby modea preferred first standby clock signal if more than one first standbyclock signal is available to the WLAN communication device.
 29. The WLANcommunication device of claim 24, further adapted to receive the atleast one first standby clock signal from an analog first standby clockoscillator.
 30. The WLAN communication device of claim 24, furtheradapted to receive the at least one first standby clock signal from adigital first standby clock oscillator.
 31. The WLAN communicationdevice of claim 24, further adapted to be installed on a host computersystem for providing WLAN communication functionality to the hostcomputer system and to receive the at least one first standby clocksignal from at least one first standby clock oscillator within the hostcomputer system.
 32. The WLAN communication device of claim 1, whereinthe control unit comprises a counting unit for counting the number oftime intervals of a predetermined length that have been elapsed sincethe WLAN communication device has entered the first standby mode. 33.The WLAN communication device of claim 32, wherein the control unitfurther comprises a timing control unit connected to the counting unitfor making the counting unit start and/or stop counting by sending acounting start signal or counting stop signal to the counting unit,respectively.
 34. The WLAN communication device of claim 33, wherein thecontrol unit further comprises a multiplexer for forwarding a main clocksignal from the physical connection unit or a first standby clock signalfrom at least one first standby clock oscillator to the counting unitand the timing control unit while the WLAN communication device is inthe first standby mode.
 35. The WLAN communication device of claim 34,wherein the counting unit is adapted to count the number of timeintervals based on the main clock signal or the first standby clocksignal received from the multiplexer.
 36. The WLAN communication deviceof claim 34, further comprising at least one frequency divider forreducing the frequency of the at least one first standby clock signaland/or the frequency of the main clock signal before providing the atleast one first standby clock signal and/or the main clock signal to thecounting unit and the timing control unit.
 37. The WLAN communicationdevice of claim 34, further comprising at least one frequency dividerfor reducing the frequency of the at least one first standby clocksignal and/or the frequency of the main clock signal before providingthe at least one first standby clock signal and/or the main clock signalto the multiplexer.
 38. The WLAN communication device of claim 34,wherein the timing control unit is adapted to select a clock signalamong the main clock signal and the at least one first standby clocksignal to be passed trough the multiplexer to the timing control unitand the counting unit.
 39. The WLAN communication device of claim 33,wherein the timing control unit is adapted to determine whether thenumber of time intervals counted by the counting unit corresponds to ascheduled duration of the first standby mode.
 40. The WLAN communicationdevice of claim 1, wherein the WLAN communication device is adapted tobe installed on a host computer system for providing WLAN communicationfunctionality to the host computer system; wherein the WLANcommunication device is further operable in a second standby mode;wherein the WLAN communication device is further adapted to disable adata packet exchange link to the host computer system when entering thesecond standby mode; wherein the WLAN communication device is furtheradapted to disable a communication link over the wireless communicationmedium when entering the second standby mode; and wherein the physicalconnection oscillator is active while the WLAN communication device isin the second standby mode.
 41. The WLAN communication device of claim40, further adapted to automatically enter the second standby mode oncethe WLAN communication device has been activated.
 42. The WLANcommunication device of claim 1, wherein the WLAN communication deviceis adapted to be installed on a host computer system for providing WLANcommunication functionality to the host computer system; wherein theWLAN communication device is further operable in a third standby mode;wherein the WLAN communication device is further adapted to disable adata packet exchange link to the host computer system when entering thethird standby mode; and wherein the WLAN communication device is furtheradapted to receive a request to enter the communication mode over thewireless communication medium while the WLAN communication device is inthe third standby mode.
 43. The WLAN communication device of claim 1,adapted to abandon the first standby mode periodically for determiningwhether a request to enter the communication mode has been received. 44.The WLAN communication device of claim 1, adapted to abandon the firststandby mode periodically for receiving a beacon signal indicating thepresence of a WLAN communication counterpart within the WLAN network.45. The WLAN communication device of claim 1, adapted to negotiate aduration of the first standby mode with a WLAN communication counterpartwithin the WLAN network and to abandon the first standby mode after thenegotiated duration.
 46. The WLAN communication device of claim 1,adapted to be installed on a host computer system comprising a CPU(Central Processing Unit) for providing WLAN communication functionalityto the host computer system, wherein the WLAN communication device isfurther adapted to negotiate a duration of the first standby mode withthe CPU and to abandon the first standby mode after the negotiatedduration.
 47. The WLAN communication device of claim 1, adapted to beinstalled on a host computer system comprising a CPU (Central ProcessingUnit) for providing WLAN communication functionality to the hostcomputer system, wherein the WLAN communication device is furtheradapted to abandon the first standby mode upon reception of a firststandby abandon signal from the CPU.
 48. A method of operating a WLANcommunication device for performing communication in a WLAN (WirelessLocal Area Network) network, comprising: operating a physical connectionunit for providing a physical connection of the WLAN communicationdevice to a wireless communication medium; operating a physicalconnection oscillator for providing a physical connection clock signalto the physical connection unit; operating a control unit forcontrolling operation of the physical connection oscillator; operatingthe WLAN communication device in a communication mode for transmittingand/or receiving data packets and a first standby mode; and deactivatingthe physical connection oscillator when the operation of the WLANcommunication device enters the first standby mode.
 49. The method ofclaim 48, further comprising requesting a transition of the operation ofthe WLAN communication device into the first standby mode by sending afirst standby request signal to the control unit.
 50. The method ofclaim 49, further comprising acknowledging reception of the firststandby request signal by the control unit by returning a requestconfirmation signal.
 51. The method of claim 48, further comprisingscheduling a duration of the first standby mode by sending a firststandby duration signal to the control unit.
 52. The method of claim 48,further comprising operating a MAC (Medium Access Control) unit formanaging communication in the WLAN network by coordinating access to thewireless communication medium.
 53. The method of claim 52, furthercomprising activating and/or deactivating the MAC unit by sending to theMAC unit an activate signal or deactivate signal, respectively.
 54. Themethod of claim 53, further comprising deactivating and/or activatingthe MAC unit when the operation of the WLAN communication device entersor abandons the first standby mode, respectively.
 55. The method ofclaim 53, further comprising acknowledging reception of the activatesignal by the MAC unit by returning an activation confirmation signal.56. The method of claim 52, further comprising operating a BBP (BaseBand Processor) unit for converting communication signalsinterchangeable over the wireless communication medium into digital datapackets processable by the MAC unit and/or vice versa.
 57. The method ofclaim 56, further comprising exchanging the digital data packets betweenthe BBP unit and the MAC unit.
 58. The method of claim 56, whereinoperating the BBP unit further comprises exchanging the communicationsignals with the physical connection unit.
 59. The method of claim 56,further comprising operating an integrated baseband medium access unitincluding the MAC unit and the BBP unit.
 60. The method of claim 59,further comprising operating the integrated baseband medium access unitincluding the control unit.
 61. The method of claim 48, whereinoperating the physical connection unit comprises operating a frequencydivider for generating a main clock signal by dividing the frequency ofthe physical connection clock signal.
 62. The method of claim 61,wherein operating the physical connection unit further comprisesproviding the main clock signal to the control unit.
 63. The method ofclaim 61, wherein operating the physical connection unit furthercomprises providing the main clock signal to a MAC (Medium AccessControl) unit for managing communication in the WLAN network bycoordinating access to the wireless communication medium.
 64. The methodof claim 61, wherein operating the physical connection unit furthercomprises providing the main clock signal to a BBP (Base Band Processor)unit for converting communication signals interchangeable over thewireless communication medium into digital data packets processable by aMAC (Medium Access Control) unit for managing communication in the WLANnetwork by coordinating access to the wireless communication mediumand/or vice versa.
 65. The method of claim 48, further comprisingdeactivating and/or activating the physical connection oscillator bysending to the physical connection oscillator a deactivate signal oractivate signal when the operation of the WLAN communication deviceenters or abandons the first standby mode, respectively.
 66. The methodof claim 48, further comprising operating at least one internaloscillator within the WLAN communication device in addition to thephysical connection oscillator for providing a clock signal to at leastone component of the WLAN communication device.
 67. The method of claim66, further comprising deactivating and/or activating the at least oneinternal oscillator by sending a deactivate signal or activate signal tothe at least one internal oscillator when the operation of the WLANcommunication device enters or abandons the first standby mode,respectively.
 68. The method of claim 48, further comprising operatingthe WLAN communication device installed on a host computer systemcomprising a CPU (Central Processing Unit) for providing WLANcommunication functionality to the host computer system.
 69. The methodof claim 68, further comprising sending a first standby abandon signalfrom the CPU to the control unit for abandoning operating the WLANcommunication device in the first standby mode.
 70. The method of claim68, further comprising exchanging digital data packets between the CPUand a MAC (Medium Access Control) unit for managing communication in theWLAN network by coordinating access to the wireless communication mediumwithin the WLAN communication device.
 71. The method of claim 48,wherein operating the WLAN communication device in the first standbymode comprises receiving at least one first standby clock signal from atleast one first standby clock oscillator.
 72. The method of claim 71,wherein operating the WLAN communication device in the first standbymode further comprises receiving the at least one first standby clocksignal by the control unit.
 73. The method of claim 71, furthercomprising determining before entering the first standby mode whetherthe at least one first standby clock signal is available to the WLANcommunication device.
 74. The method of claim 71, further comprisingdetermining before entering the first standby mode whether more than onefirst standby clock signal is available to the WLAN communicationdevice.
 75. The method of claim 74, further comprising determiningbefore entering the first standby mode a preferred first standby clocksignal if more than one first standby clock signal is available to theWLAN communication device.
 76. The method of claim 71, wherein operatingthe WLAN communication device in the first standby mode comprisesreceiving the at least one first standby clock signal from an analogfirst standby clock oscillator.
 77. The method of claim 71, whereinoperating the WLAN communication device in the first standby modecomprises receiving the at least one first standby clock signal from adigital first standby clock oscillator.
 78. The method of claim 71,further comprising: operating the WLAN communication device installed ona host computer system for providing WLAN communication functionality tothe host computer system; and wherein operating the WLAN communicationdevice in the first standby mode comprises receiving the at least onefirst standby clock signal from a first standby clock oscillator withinthe host computer system.
 79. The method of claim 48, further comprisingcounting by a counting unit within the control unit the number of timeintervals of a predetermined length that have been elapsed since theoperation of the WLAN communication device has entered the first standbymode.
 80. The method of claim 79, further comprising initiating and/orterminating counting the number of the elapsed time intervals by sendinga counting start signal or counting stop signal, respectively, from atiming control unit within the control unit to the counting unit. 81.The method of claim 80, further comprising providing a main clock signalfrom the physical connection unit or at least one first standby clocksignal from at least one first standby clock oscillator over amultiplexer to the counting unit and the timing control unit.
 82. Themethod of claim 81, wherein counting the number of the elapsed timeintervals comprises counting the number of the elapsed time intervalsbased on the main clock signal or based on the at least one firststandby clock signal.
 83. The method of claim 81, further comprisingreducing the frequency of the main clock signal or the at least onefirst standby signal, respectively, by means of a frequency dividerbefore providing the main clock signal or the first standby signal,respectively, to the counting unit and the timing control unit.
 84. Themethod of claim 81, further comprising reducing the frequency of themain clock signal or the at least one first standby signal,respectively, by means of a frequency divider before providing the mainclock signal or the first standby signal, respectively, to themultiplexer.
 85. The method of claim 81, further comprising selecting aclock signal among the main clock signal and the at least one firststandby clock signal to be passed through the multiplexer to the timingcontrol unit and the counting unit.
 86. The method of claim 79, furthercomprising determining whether the number of time intervals counted bythe counting unit corresponds to a scheduled duration of the firststandby mode.
 87. The method of claim 48, further comprising: operatingthe WLAN communication device installed on a host computer system forproviding WLAN communication functionality to the host computer system;operating the WLAN communication device in a second standby mode;disabling a data packet exchange link between the WLAN communicationdevice and the host computer system when the operation of the WLANcommunication device enters the second standby mode; disabling acommunication link of the WLAN communication device over the wirelesscommunication medium when the operation of the WLAN communication deviceenters the second standby mode; and actively operating the physicalconnection oscillator while the WLAN communication device is operated inthe second standby mode.
 88. The method of claim 87, further comprisingautomatically entering the operation of the WLAN communication device inthe second standby mode once the WLAN communication device has beenactivated.
 89. The method of claim 48, further comprising: operating theWLAN communication device installed on a host computer system forproviding WLAN communication functionality to the host computer system;operating the WLAN communication device in a third standby mode;disabling a data packet exchange link between the WLAN communicationdevice and the host computer system when the operation of the WLANcommunication device enters the third standby mode; and receiving by theWLAN communication device a request to enter the communication mode overthe wireless communication medium while the WLAN communication device isoperated in the third standby mode.
 90. The method of claim 48, furthercomprising abandoning the first standby mode periodically fordetermining whether a request to enter the communication mode has beenreceived.
 91. The method of claim 48, further comprising abandoning thefirst standby mode periodically for receiving a beacon signal indicatingthe presence of a WLAN communication counterpart within the WLANnetwork.
 92. The method of claim 48, further comprising: negotiating aduration of the first standby mode with a communication counterpartwithin the WLAN network; and abandoning the first standby mode after thenegotiated duration.
 93. The method of claim 48, further comprising:operating the WLAN communication device installed on a host computersystem comprising a CPU (Central Processing Unit) for providing WLANcommunication functionality to the host computer system; negotiating aduration of the first standby mode with the CPU; and abandoning thefirst standby mode after the negotiated duration.
 94. The method ofclaim 48, further comprising: operating the WLAN communication deviceinstalled on a host computer system comprising a CPU (Central ProcessingUnit) for providing WLAN communication functionality to the hostcomputer system; receiving a first standby abandon signal from the CPU;and abandoning the first standby mode upon reception of the firststandby abandon signal.
 95. An integrated circuit chip for performingcommunication in a WLAN network, the integrated circuit chip comprising:a physical connection circuit for providing a physical connection of theintegrated circuit chip to a wireless communication medium; a physicalconnection oscillator circuit connected to the physical connectioncircuit for providing a physical connection clock signal to the physicalconnection circuit; and a control circuit connected to the physicalconnection oscillator circuit for controlling operation of the physicalconnection oscillator circuit; wherein the integrated circuit chip isoperable in a communication mode for transmitting and/or receiving datapackets and in a first standby mode; and wherein the control circuit isadapted to deactivate the physical connection oscillator circuit whenthe integrated circuit chip enters the first standby mode.
 96. Acomputer system for performing communication in a WLAN network, thecomputer system comprising: a physical connection device for providing aphysical connection of the computer system to a wireless communicationmedium; a physical connection oscillator connected to the physicalconnection device for providing a physical connection clock signal tothe physical connection device; and a control device connected to thephysical connection oscillator for controlling operation of the physicalconnection oscillator; wherein the computer system is operable in acommunication mode for transmitting and/or receiving data packets and ina first standby mode; and wherein the control device is adapted todeactivate the physical connection oscillator when the computer systementers the first standby mode.